The inventive concept relates to semiconductor devices and to methods of fabricating semiconductor devices. In particular, the inventive concept relates to three-dimensional (3D) semiconductor devices and to methods of fabricating 3D semiconductor devices.
More highly integrated semiconductor devices are required to satisfy consumer demands for electronic products that offer superior performance and yet which are relatively inexpensive. This is especially true of semiconductor memory devices. In the case of a typical two-dimensional or planar semiconductor memory device, the integration (density) of the device mainly corresponds to the area occupied by a unit memory cell of the device. Accordingly, the degree to which a two-dimensional or planar semiconductor memory device can be integrated greatly depends on the level of fineness of patterns that can be formed by patterning techniques in the device manufacturing process. However, cost savings that may be realized when increasing the degree of integration of two-dimensional or planar semiconductor devices are offset by the prohibitive expense associated with processing equipment needed to form extremely fine patterns. To overcome such a drawback, three-dimensional semiconductor memory devices having three-dimensionally arranged memory cells have been recently proposed.